The Point of the Law is to Discriminate
The first point we need to note is that equality always means equality under the law. The point of the law is to group people under the categories of the law and treat each of them according to the categories, or to put it simpler, to discriminate according to the categories of the law. Our tax laws discriminate people into categories of their income groups, their family status, etc, and applies a different tax rate according to each category. We have elaborate legal procedures to discriminate between the innocent and the guilty with regards to a charge, and then we discriminate between them by putting the latter in jail and setting the former loose.

This principle of discriminating under the law is often known as “formal justice” or equality under the law, but because of the contentious meaning of “equality”, I prefer to call this the “consistency of the law”. Now, a violation of legal consistency would occur if say, there is a law which says that all companies with net profits of over a million would be required to pay a 20% corporate tax, but yet somehow the IRAS doesn’t make Apple pay that tax. Now that would be a “discrimination”, because the law is equally applicable to all, and if the Apple corporation does have net profits of over a million, then they fall under this law and ought to conform to it. This is the consistent application of the law.

So when a question of “discrimination” comes up, the question is always with regards to, (1) The group or people category involved and (2) The action pertaining to that group/people category.

Sexual Identity and Marriage Laws
Once we’ve considered this, there is something curious about marriage laws. The law which does not permit gay marriages does not pertain to group or people category but to the action involved. It just says that no one is allowed to contract a marriage with a person of the same sex. This law is equally applicable to ALL persons, heterosexuals, homosexuals, bisexuals, asexuals, etc. This law doesn’t discriminate against homosexuals simply because it is a law which is equally applicable to heterosexuals and bisexuals as well, those sexual orientation groups or people category fall equally under the law and are not allowed to contract a marriage with a person of the same sex as well.

Now on the surface, it seems as if I’ve just pulled off some linguistic trick. (Yay for training in analytic philosophy!) One might argue, it is like saying that the law which prohibits the celebration of the Eucharist doesn’t discriminate against Christians but is equally applicable to Muslims, Hindus and Sikhs as well. But common sense tells us that although this law technically doesn’t violate formal justice, but it clearly does “discriminate” (in some substantive sense) against Christians and is a substantive discrimination, beyond mere formal legality.

Fair enough. Equality under the law or discrimination according to legal categories isn’t always a “just” discrimination in some substantive sense. (Although one might want to ask what is “true” justice. In the words of Alasdair Macintyre, whose justice? which rationality?) Maybe, as staunch libertarians and hard core free market advocates argues, tax laws which discriminate people according to their income groups is an unjust discrimination and we should have just one uniform flat tax rate across all income group, an equal tax rate for all, what could be fairer? But I suspect many wouldn’t buy this argument.

Still, there is therefore the question as to whether preventing a same-sex contract of marriage is a substantive unjust discrimination, although technically it wouldn’t be a formal discrimination against homosexuals since the law is equally applicable across all people groups.

Free Contract of Marriage for All and to Anyone?
However it is very hard to see how exactly is the law preventing a same-sex marital contract substantively discriminatory. Perhaps one might argue that there is a more general principle, say, everyone should be allowed to contract a marriage with anyone, preventing a contract of marriage to someone of the same sex therefore a discrimination against this principle.

Unfortunately, nobody and I mean, not even LGBT groups, believes in this principle (okay, maybe nobody is too strong and absolute, a better qualifier would be, very very few people). Very few people, for example, believes that children should be allowed to contract a marriage, nor that adults should be allowed to contract a marriage to children. Nor does even homosexual lobby groups believe that we should be allowed to contract a marraige with someone within the bounds of incest, nor are people willing to say that people who have already contracted a marriage be allowed to contract another, which is simply the practice of polygamy.

It is interesting to observe with regards to this rule that when Britain was debating the civil union bill, it was constantly repeated that this was not a marriage, so a conservative MP said, okay, if this is not a marriage, I will propose an amendment to remove the incestuous limit upon civil unions. Now this is important because of heavy inheritance tax which the Western nations generally have but which civilly united couples are exempt. So if say I am living alone with my father after my mother has died, why should I not enter into a civil union with my father to avoid inheritance taxation? But strangely enough, this amendment was rejected outright by the House, and one can’t help wonder, if homosexual groups, somewhat inconsistently, want to retain as much of the “magic” of heterosexual marriage as possible.

So given these other limitations which exists within marital laws, which not even the LGBT groups want to remove, then clearly there cannot possibly be an appeal to the more general principle that anyone should be allowed to contract a marriage with anyone, because we most certainly do not believe that daughters should be allowed to marry their fathers, etc.

Conclusion
Given these cursory considerations, it is hard to see exactly why a law prohibiting the same-sex marriage is substantively discriminatory. But then again, as I’ve argued and explain for a long time, what we understand by marriage today, is a distinctly Christian invention (or gift of God!). Monogamy, life-long union, heterosexuality, etc, are all products of Western Christendom and my many other notes explain them in greater detail.

In particular, the law against infant marriages is fundamentally based upon the Catholic conception of marriage that consent makes a marriage and therefore one needs to be sufficiently “rational” to give such a consent, for incest, it is clear one of the fundamental ends of marriage is child bearing, which an incestuous couple cannot do so responsibly without deformities.

At the end, it is not so easy to see why the prohibition of same-sex marriage is discriminatory, but it would be no easy task to unwind an institution which has taken the Church and Western Christendom to develop over the centuries, and not have it collapse completely to pieces.

In fact, I think it is impossible. Still, revolutionaries love to experiment and play around with the fate of entire human communities no?

[P.S.:

It is interesting that something similar to this argument has been argued by our Attorney General in a lawsuit challenging 377A which criminalises homosexual acts. The gist of the Attorney General’s argument is that the law is not discriminatory because it is equally applicable to both gays and straights, regardless of sexual orientation. Thus, a straight person who does homosexual acts would be equally liable to be charged under this law as a gay person and the law is applied equally and without discrimination.]